1. Field of the Invention
The present invention relates to joints for connecting two members for pivotal motion relative to each other and, in particular embodiments, to joints that provide a bias torque that changes with changes in position along the pivotal motion of the two members. In certain embodiments, the bias torque is selected to equal, but oppose, other torques acting on one or both of the members, such as a torque created by gravity on one or both of the members. Further embodiments are directed to methods of making and using such joints.
2. Related Art
Connection joints for connecting two members for relative pivotal motion have been used in a variety of contexts, including, but not limited to consumer items, industrial equipment, military equipment and the like. In many contexts, it is desirable for the pivotal member to be able to pivot to any one of multiple pivot positions, and then remain in the desired position, without external support. In other words, in certain contexts it is desirable for the pivot member to be self-supporting or self-balancing at any one of multiple pivot positions.
Thus, for example, a light emitting device, a tool, a weapon or other suitable implement carried on a pivotal support arm, may be moved to a desired pivot position, by pivoting the support arm. Once moved to the desired position, it can be further desirable for the arm to remain in that position, without requiring external support to do so. Accordingly, certain joints have been formed with threaded nuts that can be tightened on a threaded shaft to grip and hold an arm in a desired position.